Alternating-current electromagnetic control-switch.



I. T. SKINNER. ALTERNATING CURRENT ELECTROMAGNETIC CONTROL SWITCH.

' APPLICATION FILED JAN. 28, 1915. 1,230,934..

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Patented J une 26, 1917.

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J. T. SMNNER. NG CURRENT ELECTRO ALTERNATI MAGNETIC CONTROL SWITCH.

APPLICATION FILED JAN-28,1915

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UNITED STATES PATENT OFFICE,

I JOHN '1. SKINNER, OF LAWRENCE, KANSAS.

ALTEBNATIN G-CUBBENT ELECTROMAGNETIC CONTROL-SWITCH.

Specification of Letters Patent. Patented 11110 26, 191 '7.

Application filed January 2a, 1915. Serial in. 4,856.

To all whom it may concern:

Be it known that 1,, JOHN T. SKINNER, a citizen of the United States,residing at Lawrence, in the county of Douglas and Stateof Kansas, haveinventedcertain' new and useful Improvements in Alternating CurrentElectromagnetic Control-Switches; and I do declare the following to be afull,

clear, and exact description of the inven- Y expensive to produce, andsilent in opera tion.

Another object of this invention resides in providing anelectro-magnetic switch controlled by an alternating currentand havingmeans to compensate for the vibratory movement. conveyed to the variousworking parts of the switch byreason of the pulsating current employedto operate the same.

Another and still further object of this invention is to provide aswitch which may be used in a high tension circuit and have ample meansto insulate the controlled from the controlling circuit.

Another and still further object of this invention resides in providinga switch having the parts thereof so balanced as to enable the operationthereof with a minimum amount of current.

Another and still further object resides in providing novel means for yeldably;

mounting the solenoids and the switch contact of the controlled circuit.2 I

With these and other objects in view, the invention consists of certainnovel features of construction, and the combination and arrangement ofparts as will be more fully.

described and claimed.

In the accompanying drawings, in which corresponding parts are indicatedby similar reference characters,

Figure l is a front elevation of my improvedswitch with the frontportion of the casing removed, certain of the parts being shown insection;

Fig. 2 is a transverse vertical section taken on the line 22 of Fig. 1;

Fig. 3 is an enlarged vertical section taken on the line 3-3 of Fig. 1;

, Fig. 4 is a transverse vertical section takenon the line 44 of Fig. l.

In controlling electric circuits especially street lights, and park andboulevard lightlng systems, etc., at points where a high voltage seriesline would beobjectionable, patrol service too expensive and timeswitches expensive, annoying and undesirable, where these points arewithin a convenient distance of an-established alternating circuit, itis frequently desirable to employ a series control device for suchsystems, which is positive and reliable in action as well asonecapableof being maintained at a v comparatively low cost. In many Instancessuch a device would save considerable first cost of construction, in-

asmuch as while low voltage conduits could be carried from theestablished alternating circuit in the immediate vicinity of the switchto the latter at a very small expense, the construction of a highvoltage series loop to and from the lamps or circuit desired to becontrolled, would be extremely impractical, therefore, it is to this endthat I have provided the switch under consideration' by means of whichelectric circuits of motors and lamps, etc., may be convenientlycontrolled by means of a'very-small amoun of alternating current.Referring more particularly to the illustrative embodiment of myinvention, 1 com: prises a casing of rectangular formation preferablyconstructed of metal. This casing isformedin two parts to wit: A front 1anda back 1", the former being detachably connected to the latter in anysuitable manner. The front 1 is provided near the top and bottom thereofwith openings 1 by means of which the casing may be ventilated. In orderthat the casing may be readily adapted to any support or may dependtherefrom as demand requires, said casing is provided with aperturedattaching ears 3 through which suitable fastening elements may bepassed. lVithin the casing 1 1s a substantially rectangular frame 4mounted centrally with respect to the casing, upon bolts 5 which passthrough the frame 4 and engage seats 6.

Centrally arranged within the frame 4 are two U-shaped brackets 7 whosehorizontal legs are disposed in opposite directions and whose verticalportions are arranged in parallel and spaced relation, said horizontallegs being attached to the top and bottom of the frame 4 by suitablefastening elements. Extending in horizontal planes are two pairs ofsupporting bars 8,

one upper and one lower, said bars being formed of insulating materialand the respective pairs thereof disposed in vertically spaced relation.To support thefree ends of the bars 8, the frame 4 is provided withlaterally extending shelves 9 which are aper tured at their outer endsto receive the bolts 10 passing transversely through the bars 8 and theopenings formed in the shelves 9, said bolts being retained in positionby ordinary retaining nuts. Vertically disposed between the bars 8 at apoint central thereof, is a rod 12 whose upper end passes through asuitable opening formed in the auxiliary guide plate 12 which extendstransversely across the central portions of the uppermost pair of bars.

Extending'transversely across the lowermost pair of bars -8 are twocontacts 13, one of said contacts being disposed on each side of the rod12 as clearly shown in Fig. 1. In order to provide connecting means forthe terminals of the controlled circuit, these contacts 13 have theirends extended as at 14 so as to project beyond the bars, and the endsthus extended areprovided with binding posts 15 as clearly shown inFigs. 1 and 2.

Disposed upon the rod 12 is, a'sleeve 16 whose lower end rests upon awasher 17 which is supported by a laterally projecting stud 18 on therod 12. The upper end of the sleeve 16 supports a washer 19, upon whichrests an annular copper plate 20, the function of which is to bridge thecontacts 13 and control the remote circuit as will be readilyunderstood; The sleeve 16 is made of insulating material to provideinsulating means for the rod 12 should the same accidentally come incontact with the contacts 13. To yieldingly maintain the copper plate 20in engagement with the washer 19 a spring 21 is interposed between awasher 22 anda washer 23 resting on the upper surface of the bridgingplate 20 and in this connection it will be seen that the upper washer 22is prevented from moving 55 by the laterally projecting stud 23' carriedby the rod 12.

The purpose of the foregoing structure, is to enable the rod 12 whichcarries the contact plate 20 to vibrate without disturbing said plate,when the latter is in engagement with the two contacts 13 as will bereadily understood without further description.

Extending through the vertical portions of the bracket 7 contiguous tothe lower ends thereof, is a bolt 24 which is held in place by afastening nut 25. Pivotally mounted intermediate of its ends upon saidbolt 24 and between the bars 8, is a lever 26 formed of insulatingmaterial. The central portion of the lever 26 is reduced and providedwith metallic side pieces 27 which enable it to move freely upon thebolt 24 with a minimum amount of friction. The. extremities of the lever26 are also reduced and provided with clips 28 which latter carrytransverse pins 29 and 30. To engage the pin 29 the rod 12 has its lowerend apertured so that said pin 29 may pass therethrough and thuspivot-ally connectone end of thelever 26 to the lower end of the rod 12for a purpose to be hereinafter set forth.

Projecting through the top of the frame 4 in spaced relation are fourpins or pivot bolts 31 and to the free end of each of said bolts issecured a link 32 having a transverse pin at the lower extremitythereof. Between each pair of the links 32 is arranged a resilient strip33, the extremities of said strip being engaged with the transverse pinscarried by said links 32. A pair of solenoids 34 having insulating endpieces 34' are secured to the strips 33 by the bar 34" which is suitablysecured to the central portion of the upper end piece of solenoids 34and has its extremities connected by rivets or otherwise to the centralportion of the resilient strips 33. By connecting the solenoids in thismanner, it will be seen that the same are yieldably supported by thebolts 31. The lower insulating end piece 34 intermediate its ends hasformed thereon a lateral extension 34" which is provided with an-openingadjacent the free end thereof. This extension as will be seen byreferring, to Fig. 1 of the drawings, projects toward the inner side ofthe'frame 4 for a purpose herein-' of said bracket and extend throughthe end piece of said solenoid. To yieldably retain the extension 34 ina central position upon the bolt 36, two springs 37 are provided asclearly shown in Fig. 1. Furthermore, as it would be undesirable to haveany current reach the frame 4, the bracket 35 is insulated from thelatter by a suitable insulating material.

From the above it will become apparent that any vibration due to thealternating current employed to energize the solenoids 34, will bereadily permitted by reason of the yieldable mounting hereinbeforedescribed. Each of the electro-magnets 34 is provided with a centrallyarranged longitudinally extending annular opening 38 having therein athin smooth non-magnetic tube 39. A U-shaped laminated plunger has oneof its legs disposed in each of the tubes 39 in the solenoids 34 so thatwhenever said solenoids are energized, the plunger will be drawnupwardly as will be readily understood without further description. Tothe intermediate portions of the horizontal part of the plunger 40 isconnected the yoke-shaped resilient plate 41. Passing throu h thehorizontal leg of the plates 41 is a olt 42 having a transverse openingat its lower end through which passes a pin 43, this pin 43 pivotallysupporting the link 44 which latter carries at its free end, atransverse pin 45 which extends through the apertured end of the rod 46,the lower end of said rod being also apertured to receive the pin 30carried by the free end of the lever 26. Hence when the solenoids 34 areenergized their plungers will be drawn upwardly, which will of courseactuate the rod 46 and thus elevate one end of the lever 26 so as tobring the contact plate 20 into engagement with the two contacts 13 andproject the same.

On the same side of the frame 4 as the U-shaped bracket 35 andimmediately below the latter, is a terminal plate 47 having bindingposts 48 and 49, said terminal plate being properly insulated from theframe 4 to prevent short circuiting of the current as will be readilyunderstood. Also secured to this side of the frame4 immediately abovethe terminal plate 47 is another terminal plate 50 having binding posts51 and 52. The bottom of the frame 4 is formed with a series of spacedopenings which register with similar openings formed in the bottom ofthe casing 1, and within these openings are disposed insulating sleeves53. Passing through the sleeves 53 are the four conductors 54, 55, 56and 57. The conductors 56 and 57 extend from the controlled circuit andhave their upper ends connected to the binding posts'15 on the contacts13, while the conductors 54 and 55 extend'from the controlling circuitand are connected to the binding posts 51 and 48 respectively.

In order to convey the current to the solenoids 34, a conductor 58 hasone end connected to the binding post 49 and the other to one terminalof one of the solenoids 34, while the other terminal of said solenoidsis connected by a conductor 59 to binding post 52 on the terminal plate50.

From the above connections it will be apparent that alternating currentcoming from the source of supply through the conductor 54 will beconducted to the terminal plate 47 and thence through the conductor 58to the solenoids 34; .from these it will be carried by the conductor 59to the terminal plate 50 and from the latter by conductor 55 to thesource of supply. This alternating current will energize the solenoids34, actuate the plunger and bring the annular metallic plate 20 intocontact with the two contacts 13; to thus close the controlled circuitso that current may flow through the conductor 56, contact 13, plate 20,and return to conductor 59, all of which will be apparent on referringto Fig. 1 of the drawings. To prevent the one end of the lever 26 fromviolently contacting with the bottom of the frame 4, a rubber bumper 60is disposed immediately below the lower end of the rod 46.

Thus, it will be seen that the rod 46 and rod 12 together with itscontact plate, and means for yieldably supporting the same, areapproximately balanced, and that the weight of the plunger is justsufficient to maintain the plate 20 in disengaged position when thesolenoids 34 are deenergized, so that the solenoids 34 instead of beingcompelled to actuate the switch, simply has to lift its plunger, and thecontact plate 20 will be lowered so as to close the controlled circuit.In other words, the rod 12 together with the plate 20 and means forsupporting the same are heavier than the rod 46 without the weight ofthe plunger 40. This means that the movable parts of the switch may beactuated by means of a very small amount of current, in fact only suchcurrent as would be necessary to lift the plunger, of the magnet.

Thus it will be seen that I have provided a switch which is very simpleyet extremely eflicient, and one which will be certain in operationunder all conditions.

Although in the foregoing I have described certain elements as bestadapted to perform the functions ascribed to them, nevertheless it is tobe understood that various changes as to form, substance, etc., may beresorted to within the scope of the appended claims without departingfrom or sacrificing any of the principles of the invention.

I claim:

1. A device of the class described comprising a casing, a pair ofU-shaped brackets arranged within said casing, the legs of said bracketsextending horizontally infopposite directions and being secured to thetop and bottom of the latter, the intermediate portions of said bracketsbeing arranged vertically, vertically spaced pairs of upper and lowerhorizontal supporting bars secured at one of their ends to the verticalportions of said brackets and having their other ends secured to oneside of said casing, a guide plate extending transversely across thecentral portions of the upper supporting bars and having an openingtherein, a pair of horizontally spaced contacts transversely across thelower supporting bars, a vertically disposed rod slidably re ceived atits upper end in the opening in said guide plate and having its lowerend disposed between said contacts, a contact bridging plate carried bysaid rod, and means for actuating said rod.

2. A device of the class described comprising a'casing, a pair of spacedparallel horizontal resilient strips secured at their extremities to thetop of said casing, a bar sei extending cured at its extremities to thecentral porprising a casing, 'a vertically disposed solenoid movablyconnected at its upper end to the topof said-casing, a lateral extensionat the lower endofjsaid solenoid and having an aperture therein, a.bracket attached to one side ofysaid, casing and having a pair of legsprojecting horizontally and 'in vertically spaced relation therefrom, ain arranged vertically betwensaid-legsjsiri fixed thereto, said pinextending through the aperture in the solenoid extension, coiledspringssur-- rounding said pin above'and beldw'the lat- 45 ter, and a plungerfor Sald SQleBQid;

In testimony whereof I have-hereunto 'sa' my hand in presence oftwo'sub'sc'ribing wit- A JOHN T.- SK I N NER.

HUeHME'ANs, L. Nl'LEWIs.

